Cleaning outdoor windows can be time consuming and labor intensive. One approach tried by the art to address these concerns was described in WO 97/48927. A sprayer depicted therein was connectible to a garden hose and also included a control valve for selective spraying of a cleaning composition or rinse water. With the control valve in a “clean” position, hose water mixed with a cleaning composition inside the sprayer to allow cleaning of windows without scrubbing.
The cleaning solution was allowed to remain on the window for a suitable time period to permit the surfactant to work. Next, with the valve in a “rinse” position, hose rinse water was filtered by an ion exchange resin to remove most of the hardness and/or other residues that cause spotting and/or filming, and after rinsing the window with that filtered water the glass could dry to a cleaner finish without the need for using a squeegee.
While this improved initial spotting performance, such windows sometimes were more prone to be spotted by rain water thereafter. As a result, in U.S. Pat. No. 6,562,142 it was disclosed to use a hose end spray device to (i) apply a cleaning solution to a surface such that the solution renders the surface hydrophilic, (ii) rinse the surface to remove at least some of the cleaning solution, and (iii) then rinse the surface with purified rinse water. This reduced initial spotting and also inhibited rain water spotting, according to the patent.
However, spray devices like those of WO 97/48927 and U.S. Pat. No. 6,562,142 still had drawbacks. For example, the device of U.S. Pat. No. 6,562,142 used multiple user-manipulated control valve flow selectors that could confuse the user as to the proper sequence of surface cleaning steps. Also, both of these devices required a user to separately replace/maintain/refill a reservoir for the cleaning composition and the water filter. This entailed extra steps in preparing and maintaining the devices for use, and some problems in operation.
Therefore, a need still exists for a sprayer of this general type that can apply a cleaning solution, rinse water and also filtered water to a surface such that the surface dries with reduced spotting, where the sprayer is easier to maintain and more intuitive to operate.